Orthodontic face bow with improved arch wire connector



Feb. 25., 1969 J. .M. RUBIN 3,429,044

ORTHODONTIC FACE BOW WITH IMPROVED ARCH WIRE CONNECTOR Filed March 26, 1964 INVENTOR :YW HTRQL'W BY K "MW ATTORNEY United States Patent Claims This invention relates generally to an orthodontic appliance and is more specifically directed to an improved orthodontic face bow and means for interconnecting the inner and outer arch wires of a face bow.

Face bows are in general use in orthodontics for the distal movement of teeth. In contradistinction to the usual type of orthodontic appliance which is placed wholly within the patients mouth, face bows are carried externnally and have portions thereof extending into the patients mouth. For this reason, face bows are generally worn when the patient is at home and when the patient is sleeping.

The face bow usually consists of an inner arch wire and an outer arch wire joined together at the longitudinal centers of the arches. The inner arch wires engages the patients teeth by means of buccal tubes or other known attachments and the wire forming the inner arch extends outwardly from the patients mouth, between his lips. Outside of the mouth, the inner and outer arch wires are joined and the outer arch wire extends around the patients face parallel to the cheeks. The outer arch wire is usually anchored to the patients head by means of a suitable harness. A variety of extra oral head caps and cervical traction straps are in common use as harnesses for occipital anchorage. Since the face bow is firmly secured relative to the patients head by the harness, all pressures and torques are applied to the particular teeth to which the inner arch wire is connected, to thereby urge these teeth in the desired direction.

It is readily understood in orthodontics that, while face bows are awkward and unsightly, their characteristics of operation are highly desirable. In the usual orthodontic appliance, brackets or buccal tubes are attached to the teeth of both the upper and lower jaws and arch wires are secured in the brackets or tubes. If distal movement of the upper molars is desired, elastics are stretched from the anterior portion of the upper arch wire to the molars of the lower jaw by means of hooks or attachments, using the lower jaw for anchorage. However, it will be readily seen that reaction forces are also applied to the lower jaw and, thus, undesired movement of the lower molar teeth or jaw may result. By the utilization of'face bows, this is avoided, as the inner arch wire is only connected to the teeth which are to be distally driven, and the reaction forces are taken up by the harness about the head.

Face bows are most advantageously used to distally drive molars, which are multi-root teeth, usually requiring greater forces than the single-root teeth.

As stated above, known constructions of orthodontic face bows'usually include an inner arch wire, and an outer arch wire brazed or soldered together with or without a connector for joining the wires. In order to join the wires through the connector, both of the wires are soldered or brazed to the connector. Unfortunately, the heat from soldering or brazing tends to soften the wire, thereby reducing its resiliency. As will be readily appreciated, the resiliency of the wire is an important factor in the application of the straightening forces. Furthermore, experience has demonstrated that the wires tend "ice to break in the area of the soldered or brazed connection, thus necessitating replacement or refabrication of the face bow.

Accordingly, it is an object of this invention to provide an improved orthodontic face bow.

A further object of this invention is to provide means for interconnecting the wires of an orthodontic face bow in such a manner that soldering or brazing is avoided.

Another object of the invention is to provides means for removably interconnecting the wires of an orthodontic face bow so that either of the wires can be replaced if required, without requiring the fabrication of a completely new face bow.

Still another object of the invention is to provide means for securely interconnecting the wires of an orthodontic face bow and controlling relative movement therebetween without the utilization of soldering or brazing.

A still further object of the invention is to provide an improved orthodontic face bow having replaceable arch wires.

A further object of the invention is to provide an orthodontic face bow having means for interconnecting the wires thereof which may permit relative movement between the wires.

Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.

Generally speaking, in accordance with the invention, a split yoke or connector is provided for interconnecting the wires of an orthodontic face bow. The yoke is pro vided with specially designed channels which prevent or permit, as required by the application, relative movement between a wire and the yoke. The yoke halves are secured together by suitable fastening means so that the yoke may be disassembled for replacement of an arch wire, if such becomes necessary. The arch wires are preformed to the configuration of the channels in the yoke for ease of assembly and proper fit.

The invention accordingly comprises the features of construction, combinations of elements, and arrangement of parts which will be exemplified in the constructions hereinafter set forth, and the scope of the invention will be indicated in the claims.

For a fuller understanding of the invention, reference is bad to the following description taken in connection with the accompanying drawing, in which:

FIG. 1 is a plan view of an orthodontic appliance constructed and assembled in accordance with a preferred embodiment of the invention;

FIG. 2 is a partial sectional view taken along line 2-2 of FIG. 1;

FIG. 3 is a partial sectional view taken along line 33 of FIG. 1;

FIG. 4 is a plan view of a half-yoke portion constructed in accordance with the invention;

FIG. 5 is a plan view of a half-yoke portion constructed in accordance with an alternate embodiment of the invention; and

FIG. 6 is a plan view of a pair of inner and outer arch wires constructed for assembly with the yoke of FIG. 5.

Referring now to FIGS. 1 through 4, the orthodontic appliance consists of an inner arch wire 11, an outer arch wire 12 and a connector or yoke 13. The inner and outer arch wires are normally fabricated from a high quality stainless steel and the curvature and length of the inner arch wire will depend upon the size of the patients mouth and the curvature of the arch. The outer arch wire is provided with books 14 for attachment to a harness or other known device.

The connector or yoke 13 is split into two identical halves 15 which, when taken together, form a single element for receiving and securing the inner and outer arch wires. A single yoke half 15 is most clearly shown in FIG. 4. The yoke half is provided with an inner groove 16 extending longitudinally along a smooth arc. As shown in FIG. 2, the inner groove has a substantially semi-circular cross section to accommodate the inner arch wire which is normally a circular wire. Yoke half 15 is also provided with an outer groove 17 which follows along the inner groove for a substantial portion of its length and which is generated from substantially the same center of curvature. As shown in FIG. 2, the semi-circular cross-sectional configuration of outer groove 17 is larger than the semicircular configuration of inner groove 16 since the gage of the outer arch wire is usually heavier than the gage of the inner arch wire. As the outer groove approaches the ends of the yoke half, the groove diverges from its path of parallelism with respect to the inner groove and forms a groove section 18 at either end extending at an obtuse angle from the main portion of the outer groove. The obtuse groove sections not only assure positive locking of the outer arch wire in the outer groove, but also carries the central portion of the outer arch wire away from the patients mouth to assure freedom from contact between the outer arch wire and the patients lip corners and checks.

Each end of yoke half 15 is provided with a Hat ear 19 disposed between the outermost ends of the inner and outer grooves. Each ear is provided with an aperture 21 for receiving a fastener for securing together two yoke halves. As shown in FIG. 1, both the inner and outer arch wires are formed to precisely follow the curvatures of the inner and outer grooves and the transition between the central portion of outer groove 17 and the obtuse groove sections is made smooth and gradual to prevent internal stress or fracture of the outer arch wire when it is formed to the configuration of the outer groove.

The inner and outer arch wires, after being preformed to the required configuration, are placed in the grooves of a yoke half 15 and a second yoke half is disposed on the opposite side of the Wires from the first yoke half, as best seen in FIG. 3. Fasteners 22 secure the yoke halves together through the apertures 21 in the flat ears 19. Fasteners 22 may be of any suitable type, with screws or rivets being preferred. Once the yoke halves are fastened, the inner and outer arch wires are rigidly secured together and relative motion therebetween is prevented especially due to the curvature of the grooves and particularly the obtuse extension of groove sections 18. In the event that either of the arch wires breaks or becomes bent or distorted, it is merely necessary to remove fasteners 22 and replace the broken or bent wire. n the other hand, a broken or bent wire in prior devices has normally required the replacement of the entire appliance. However, if it is not desired to have the arch wires removable, flat cars 19 may be welded together. Such welding will not affect the temper of the wires.

In the construction described above, the connector or yoke holds the inner and outer arch wires in a single plane which may be refined as the vertical plane passing into the drawing along the central vertical axis: of the device as shown in FIG. 2. For some orthodontic applications, it may be desirable to permit the outer arch wire to swivel out of this plane relative to the inner arch wire about the longitudinal axis of the outer arch wire. Such an application may be accomplished utilizing the alternate construction shown in FIGS. and 6, without departing from the general principles taught by the instant invention.

In the alternate embodiment, a yoke half 31 is provided with an inner groove 32 formed on a smooth arc and a straight outer groove 33 which is substantially tangential to the inner groove at the center of the arc of the inner groove. The yoke half is also provided with flat ears 34 through which pass apertures 35 to permit the fastening together of a pair of yoke halves 31 in the same manner as described in connection with the preferred embodiment. In the alternate embodiment, an inner arch wire 36 will be formed substantially the same as inner arch wire 11. However, the outer arch wire 37 will have a straight central section whose length is at least as long as the length of outer groove 33. It will be readily understood that arch wires 36 and 37 will be secured together by means of oppositely disposed yoke halves 31 utilizing fasteners (not shown) passing through apertures 35 and bearing on flat cars 34. The arcuate configuration of inner arch wire 36 secured in the channel formed by the oppositely disposed inner grooves 32 will prevent relative movement of the inner arch wire with respect to the yoke halves. However, outer arch wire 37 may rotate about the longitudinal axis through the straight section thereof within the channel defined by the oppositely disposed outer grooves 33 to permit the outer arch wire to rotate out of the plane hereinabove described. As stated in connection with the preferred embodiment, either of the arch wires may be readily replaced as required without requiring replacement of the yoke halves or the other arch wire. In fact, in either embodiment, the yoke halves can be reused indefinitely with arch wires that will be supplied to the orthodontist, preformed to the configuration of the grooves in the yokes.

It is contemplated that hooks, springs, loop and stops, all of which are known to those versed in the art, may be added to or integrally formed with the novel orthodontic appliance, within the scope of this invention.

It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained and, since certain changes may be made in the above constructions without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawing, shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

What is claimed is:

1. An orthodontic face bow comprising, an inner generally U-shaped arch wire, an outer generally U-shaped arch wire, a first yoke half disposed on one side of and engaging an intermediate portion of each of said arch wires, a second yoke half disposed on the other side of and engaging an intermediate portion of each of said arch wires, said yoke halves together forming a connector for securing said arch wires relative one to another, and fastening means engaging said yoke halves for securing said face bow in an assembled position.

2. An orthodontic face bow comprising, an inner generally U-shaped arch wire preformed to a preselected configuration, an outer generally U-shaped arch wire preformed to a preselected configuration, a first yoke half provided with inner and outer groove portions adapted to mate with the configurations of the inner and outer arch wires, said first yoke half disposed on one side of and engaging an intermediate portion of each of said arch wires, a second yoke half identical to said first yoke half disposed on the other side of and engaging an intermediate portion of each of said arch wires, said yoke halves together forming a connector for securing said arch wires relative one to another in the grooves defined by the mating yoke halves, and fastening means engaging said yoke halves for securing said face bow in an assembled position.

3. For use with a pair of generally U-shaped arch wires forming an orthodontic face bow in which an inner arch wire is received within a patient's mouth and an outer arch wire extends around the face, a yoke half comprising a formed element including first means defining an inner groove, second means defining an outer groove, said outer groove being closely adjacent said inner groove at least at the longitudinal centers thereof and being spaced and diverging from said inner groove at the longitudinal ends of said grooves, and ears formed between the spaced portions of said grooves at opposite ends of said formed element, the size of said yoke element being sufficiently small enough to accommodate intermediate portions of the arch wires within the grooves and having an overall elongated length no greater than the span between the legs of the outer arch wire to be received around a patients face.

4. For use with a pair of generally U-shaped arch wires forming an orthodontic face bow in which an inner arch wire is received within a patients mouth and an outer arch wire extends around the face, a yoke half comprising a formed element including first means defining an arcuate inner groove, second means defining an outer groove, the central portion of said outer groove being arcuately adjacent said inner groove and being formed on substantially the same center of curvature, the outer ends of said outer groove diverging at an oblique angle to the central portion thereof, and ears formed between the outer ends of said inner groove and the oblique outer ends of said outer groove at opposite ends of said formed element, the size of said yoke element being sufficiently small enough to accommodate intermediate portions of the arch wires within the grooves and having an overall elongated length no greater than the span between the legs of the outer arch wire to be received around a patients face.

5. For use with a pair of generally U-shaped arch wires forming an orthodontic face bow in which an inner arch wire is received within a patients mouth and an outer arch wire extends around the face, a yoke half comprising a formed element including first means defining an arcuate inner groove, second means defining a straight outer groove, said outer groove being tangentially adjacent said inner groove at the longitudinal center thereof, and ears formed in the space defined by the outer arcuate end of said inner groove and the outer straight end of said outer groove at opposite ends of said formed element, the size of said yoke element being sufficiently small enough to accommodate intermediate por- [ions of the arch wires within the grooves and having an overall elongated length no greater than the span between the legs of the outer arch wire to be received around a patients face.

References Cited UNITED STATES PATENTS 2,980,404 4/1961 Anderson et al. r 24868 3,111,758 11/1963 Winkler 32--14 3,121,953 2/1964 Asher 32-14 RICHARD A. GAUDET, Primary Examiner.

R. L. FRINKS, Assistant Examiner.

US. Cl. X.R. 

1. AN ORTHODONTIC FACE BOW COMPRISING, AN INNER GENERALLY U-SHAPED ARCH WIRE, AN OUTER GENERALLY U-SHAPED ARCH WIRE, A FIRST YOKE HALF DISPOSED ON ONE SIDE OF AND ENGAGING AN INTERMEDIATE PORTION OF EACH OF SAID ARCH WIRES, A SECOND YOKE HALF DISPOSED ON THE OTHER SIDE OF AND ENGAGING AN INTERMEDIATE PORTION OF EACH OF SAID ARCH WIRES, SAID YORK HALVES TOGETHER FORMING A CONNEC- 